The amount of steam released from a food product in a time interval during a cooking process in a cooking chamber of a baking oven can be determined directly, for example using a humidity sensor as described in U.S. Pat. No. 4,734,554, or indirectly, for example using an oxygen sensor, to allow for humidity-dependent control of the baking oven in order, for example, to automatically determine the end of cooking time. In this connection, it is possible to use any suitable heating source known in the art, except for heating steam, because it is impossible to distinguish between the heating steam and the steam that is released from the food product during cooking. However, the described sensor technology is relatively expensive.
Furthermore, German Patent Publication DE 44 01 642 A1 describes a steam cooking device, where the amount of steam is controlled by the heating of the cooking chamber. For this purpose, the amount of steam present in the cooking chamber is determined using a temperature sensor. The temperature sensor has a sensing part located in a condensation section, and a mounting part which is in contact with the ambient air. Therefore, the temperature occurring at the temperature sensor will be lower than the steam temperature.
Moreover, German Patent Publication DE 41 09 565 A1 describes a method, where the steam content in a cooking chamber is determined using a so-called condensate trap. In the process, the temperature variation at the condensate trap is monitored during condensation and used to automatically determine the level of steam. Thus, this method is designed for use in cooking appliances that use steam as a heating medium. In this method, it is not necessary to distinguish between the heating steam and the steam that is released from the food product during cooking, since the intention here is only to control the supply of heating steam.